It was known to be atmospheric pollutant produced by internal combustion of engines. It possesses various biological functions—there is non-specific immunity, inhibition of platelet aggregation, vasodilatation, regulation of nor-epinephrine release, etc.
Centrally there may be hyperalgesia or pain, analgesia, anaesthesia, anxiolysis, regulation of neuroendocrine system, neurotoxicity, epileptigenesis, etc.
Nitric oxide is reactive oxidation product of arginine. It is extremely labile. It is synthesized in the body and immediately diffuses out of the neuron to the target cell, after immediate nitric oxide Inhalation . It is highly reactive in the presence of oxygen. It is nonenzymatically converted by oxygen and water to various nitrates and nitrites.
Overproduction or excess nitric oxide Inhalation in the body is mostly harmful and may cause septic shock. It may produce bronchodilatation.
Nitric oxide Inhalation may cause selective reversible dose-dependent pulmonary vasodilatation. It improves ventilation and perfusion of lungs, so beneficial in adult respiratory distress syndrome. It helps to reduce pulmonary vascular resistance in patients with primary pulmonary hypertension.
Nitric oxide Inhalation may be toxic in high concentration. High levels of nitric oxide react with oxygen to form toxic oxides of nitrogen that results in tissue damage, methaemoglobinaemia, asphyxia and death. It is available as various diluents in compressed nitrogen.